1. Field of the Invention
This invention relates to sawing apparatus, and more particularly, to an apparatus which widely increases the versatility and variability of usage of standard portable chain saws by adapting such saws to utilization for making various precision cuts on trees, logs and the like in the field, and also in adapting the chain saw to use in effecting substantially horizontal precision cuts in a workpiece supported on a workbench.
2. Brief Description of the Prior Art
Chain saws are highly effective cutting devices for field work in felling trees and trimming limbs therefrom, as well as other sawing tasks which involve cutting through relatively large wooden members which are stationarily located and in situations where the main objective is severance of the member without particular regard to the precise angle or orientation of the cut. Generally, chain saws as presently constructed are portable, and include a handle by which the saw can be lifted and manipulated and some type of guard element. While the construction of chain saws varies considerably, they generally include a chain saw blade supporting and guiding plate upon which the saw blade tracks and is supported during the cutting operation. The majority of chain saws previously manufactured and sold have also included some type of guard structure intended to function to prevent contact with the saw blade during its high speed movement, and thereby prevent injury to the user. Most chain saws, even the smallest, are relatively heavy, and such weight makes it difficult to manually use a chain saw to effect cutting through a precisely predetermined plane, or at a predetermined angle with respect to a workpiece surface. Moreover, the weight and method of construction are such that it is often extremely difficult to cut small, unsupported or unanchored pieces of wood with this type of saw. In general, these characteristics make chain saws unsuited for home use in craft projects, or in carpentry operations where precision cutting of relatively small wooden workpieces is entailed. Conventional chain saws are also not adapted for field usage where a log or other structural member is to be notched or cut through in a precise plane for purposes of use in construction projects or the like.
Various types of stationary bench-mounted saw devices have previously been manufactured for providing the cutting capacity and power inherent in chain saw structures, yet permitting more or less precision cutting as required in carpentry, and for many types of home crafts. Thus, certain types of radial saws as well as band saws have been provided on various types of jigs or stands and have been susceptible to movement in several planes to effect cutting in different planes in order to produce mitered cuts, or preselected bias cuts, in various sizes of workpieces. In general, however, most of the types of saw structures which have been provided for such usage have not been susceptible to transport to field locations where they may be manipulated by hand--that is, readily located, used and relocated at will in any location which may be desired by the user. Moreover, such structures are, in general, entirely unsuited to felling and trimming trees. On the other hand, chain saw structures as they are now known, while portable and suitable for a variety of field uses, cannot be adapted in such locations to use for notching timbers, for mitering, as a beam slabbing apparatus or for any similar functions. The hand-held portable chain saws are not sufficiently stable, or precisely locatable manually, to facilitate such cutting and, of course, in most instances no structures are present which afford a stable platform to which such chain saws can be secured to give the required stability to perform the described types of cutting operations.
In an effort to realize some of the advantages of portability and the concomitant flexibility in types of field cutting which is characteristic of chain saw utilization, and also to permit bench mounting of similar types of saws, various proposals have been heretofore made for detachably or temporarily mounting various kinds of portable power saw equipment on supporting platforms or jigs to permit them to be held steadily and stationarily at a fixed location in order to effect a desired angle of cut, or a particular sawing operation. Some of these types of structures have included platforms or stands upon which chain saws can be mounted, and others have contemplated a demountable, temporary support of radial saws or other types of saws. Examples of patents which depict and describe a chain saw mounting structure for permitting a chain saw to be used as a table saw in woodworking and carpentry are U.S. Pat. No. 2,851,067; U.S. Pat. No. 1,123,783; French Pat. No. 1,384,843; German Pat. No. 740,065; French Pat. No. 1,031,907; Swiss Pat. No. 374,192, and German Pat. No. 690,791. In the case of all these patents, however, the structure in which the chain saws are mounted to permit a table sawing application to be achieved are such that the mounting of the saw in the structure for effecting a desired cut is time-consuming, and requires several manipulations using various types of hand tools. Moreover, the types of cuts, as well as the sorts of workpieces which can be cut with the structure as thus provided, are, in all cases, limited to certain specialized cutting operations. Thus, the chain saw mounting stand shown in French Pat. No. 1,384,843 is, in reality, best adapted and utilized primarily for cutting logs into relatively short segments (such as firewood), and is unsuited for cutting mitered cuts along a particular, preselected angle. The same limitation is characteristic of the saw mounting framework shown in German Pat. No. 690,791.
In Greenslate U.S. Pat. No. 2,851,067, cutting is effected by upward movement of the saw blade through the workpiece located on the top of a supporting table, and it is not possible to perceive the line of cut of the blade as it enters the workpiece from its underside. Cutting of the saw is also limited to a single vertical plane in the case of the Greenslate table-mounted chain saw structure.
The endless chain saw shown in Muir U.S. Pat. No. 1,123,783 is actually not a dual functioning type of apparatus in that the chain saw there illustrated, while platform mounted, cannot be removed and made portable for field usage. It is true that the platform upon which the chain saw blade is mounted in the Muir structure is mounted upon skids and thus constitutes a type of sled, but hand portability and ability to manually use the chain saw in the field are not characteristic of this structure.
In U.S. Pat. No. 3,433,277 to Ripley, a foldable saw buck is provided which includes a trough for holding a log, timber or other workpiece so that an end portion of the log can extend beyond the trough. There is then provided a pivotable platform upon which a portable chain saw can be clamped, and the platform then pivoted in such a way that the saw blade is caused to move through a plane which intersects and extends through the log or workpiece at a location beyond the end of the trough. This particular arrangement, while affording stability to the chain saw, does not facilitate the use of the chain saw in a field location for making precision cuts, since it would be impractical to transport the entire foldable saw buck to the field location. Moreover, the saw buck is intended to be bolted or otherwise clamped and secured to a floor or other supporting surface. Further, this apparatus has no capability of making mitered cuts, or any other cut orientation except at substantially a right angle to the axis of the workpiece or log.